12.2.2 Signal Description
| Signal | Type | Description | 
|---|---|---|
| CLKOUT | Digital output | CLK_PER output | 
| XTALHF1 | Analog input | Input for external clock source (EXTCLK) or one pin of a high-frequency crystal | 
| XTALHF2 | Analog input | Input for one pin of a high-frequency crystal | 
| XTAL32K1 | Analog input | Input for external 32.768 kHz clock source or one pin of a 32.768 kHz crystal | 
| XTAL32K2 | Analog input | Input for one pin of a 32.768 kHz crystal | 
For more details, refer to the I/O Multiplexing section.
